How to increase the number of faces in a model
It's hard to know how to help without many details. If you're following a modelling tutorial and you're supposed to have 32 faces and you only have 11, you may want to go back and double check you followed the tutorial properly.

But your question was how to increase the number of faces, and here's a few ways how...

Method 1: Using Subdivide Tool

Select your object and make sure you are in edit mode.



Click this button to enter face select mode:



Select the faces that you wish to divide by right clicking on them:



Press W, and when this menu pops up, click Subdivide:



You can repeat this as many times as you want. Each time the selected faces will be divided into 4 new faces if they are quads.



Method 2: Using Knife Tool

Again, select your object and make sure you're in edit mode:



Press K to activate the knife tool. Now you can draw lines where you want to cut your object:



And press ENTER when you are satisfied, or ESC to cancel.

Method 3: Ring Cut Tool

This is essentially a much more controlled, but limited, version of the knife tool. Once again make sure you select your object and are in edit mode. Press CTRL + R to activate the ring cut tool, and mouse over an edge. The purple line is where the cut will be made.



You can scroll up and down with your mouse to increase/decrease the number of cuts, and click to perform the cut.

At this point you can adjust the position of the cuts, or right click to keep them in the center.

Method 4: Subdivision Surface Modifier

This one is a little different. This time, make sure you are in object mode:



With your object select, go to the modifiers panel on the right (it looks like a wrench) and click Add Modifier and select Subdivision Surface.



You can adjust the number of cuts with the numbers where it says "View" and "Render". If you don't want your object to be rounded, click on Simple. Click Apply when you are satisfied.